Michael A. Newdow, a lawyer and emergency room doctor, this week filed suit in federal district court in Washington contending that it is unconstitutional for taxpayer-funded chaplains to pray in Congress and minister to lawmakers. He wants the court to prohibit the House and Senate from employing spiritual chaplains, who are paid by Congress to lead prayers, counsel members and perform other religious tasks. Chaplains make as much as $147,000 per year.